//
//  UIColor+HHHex.m
//  yisu
//
//  Created by 花花 on 2016/7/18.
//  Copyright © 2016 youle. All rights reserved.
//

#import "UIColor+HHHex.h"

@implementation UIColor (HHHex)

+ (UIColor *)colorWithHexString:(NSString *)color alpha:(CGFloat)alpha {
  //删除字符串中的空格
  NSString *cString = [[color
      stringByTrimmingCharactersInSet:[NSCharacterSet
                                          whitespaceAndNewlineCharacterSet]]
      uppercaseString];
  // String should be 6 or 8 characters
  if ([cString length] < 6) {
    return [UIColor clearColor];
  }
  // strip 0X if it appears
  //如果是0x开头的，那么截取字符串，字符串从索引为2的位置开始，一直到末尾
  if ([cString hasPrefix:@"0X"]) {
    cString = [cString substringFromIndex:2];
  }
  //如果是#开头的，那么截取字符串，字符串从索引为1的位置开始，一直到末尾
  if ([cString hasPrefix:@"#"]) {
    cString = [cString substringFromIndex:1];
  }
  if ([cString length] != 6) {
    return [UIColor clearColor];
  }

  // Separate into r, g, b substrings
  NSRange range;
  range.location = 0;
  range.length = 2;
  // r
  NSString *rString = [cString substringWithRange:range];
  // g
  range.location = 2;
  NSString *gString = [cString substringWithRange:range];
  // b
  range.location = 4;
  NSString *bString = [cString substringWithRange:range];

  // Scan values
  unsigned int r, g, b;
  [[NSScanner scannerWithString:rString] scanHexInt:&r];
  [[NSScanner scannerWithString:gString] scanHexInt:&g];
  [[NSScanner scannerWithString:bString] scanHexInt:&b];
  return [UIColor colorWithRed:((float)r / 255.0f)
                         green:((float)g / 255.0f)
                          blue:((float)b / 255.0f)
                         alpha:alpha];
}

//默认alpha值为1
+ (UIColor *)colorWithHexString:(NSString *)color {
  return [self colorWithHexString:color alpha:1.0f];
}

@end
